161645544 has 64 divisors (see below), whose sum is σ = 454608000. Its totient is φ = 53876016.

The previous prime is 161645543. The next prime is 161645569. The reversal of 161645544 is 445546161.

161645544 is a `hidden beast` number, since 1 + 6 + 1 + 645 + 5 + 4 + 4 = 666.

It is a super-2 number, since 2×161645544² = 52258563790111872, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 161645499 and 161645508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161645543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12877 + ... + 22115.

It is an arithmetic number, because the mean of its divisors is an integer number (7103250).

Almost surely, 2^161645544 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161645544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227304000).

161645544 is an abundant number, since it is smaller than the sum of its proper divisors (292962456).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161645544 is an frugal number, since it uses more digits than its factorization.

161645544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9266 (or 9244 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 161645544 is about 12713.9900896611. The cubic root of 161645544 is about 544.7383015382.

The spelling of 161645544 in words is "one hundred sixty-one million, six hundred forty-five thousand, five hundred forty-four".